The ornamental design for analytical instrument, as shown and described.
FIG. 1 is a perspective, side view of an analytical instrument;
FIG. 2 is a top view of the analytical instrument in FIG. 1;
FIG. 3 is a bottom view of the analytical instrument in FIG. 1;
FIG. 4 is a right side view of the analytical instrument in FIG. 1;
FIG. 5 is a left side view of the analytical instrument in FIG. 1;
FIG. 6 is a front, side view of the analytical instrument in FIG. 1; and,
FIG. 7 is a rear, side view of the analytical instrument in FIG. 1.
The broken line showing of structural features is included for the purpose of illustrating non-claimed subject matter and forms no part of the claimed design.